function: Does calculation of longitudinal CBM growth rates
using monopole HOMs and bunch definitions currently defined. Monopole
HOMs and a bunch pattern must have been defined previously for this
command to work. Either one of the optional commands sweepFrequency and randomizeHOMFrequencies may appear before. If both
appear, the last one takes precedence.

If the optional command sweepFrequency is in effect, the
SDDS file specified by the filename variable in that namelist
command is opened at this point.

If the optional command randomizeHOMFrequencies is in effect,
the SDDS files specified by the filename and frequencyListFilename variables in that namelist command are opened
at this point.